Code 43

[Nurega]

I've been looking around a while now, and this code appears the be most difficult to diagnose. My mechanic (an honest one) has said "don't worry about it" the last two years, but I'm interested in finding out what's actually triggering it. It throws code only the car is loaded with people and luggage, doing all highway, and pedal to the metal. Flooring it in top gear for a quick pass can trigger the code. It has never happened on cold days; the hotter the temperature is, the more likely Code 4-3 is thrown.
If anyone's had this problem with these same parameters, let me know if you were able to diagnose the problem. Fuel filter, fuel pump, etc; it could be anything related to fuel delivery, apparently.

[ikayto]

usually it's the o2 sensor. let me know if you want to borrow my o2 sensor socket

[Nurega]

oh is that right? I'd assumed the problem was in fuel delivery related. NGK would be the way to go then, yeah?

[deevergote]

The o2 sensor tells the ECU how much fuel to send, which is why the ECU sees it as a fuel system problem.

My code 43 comes on at about 55mph, and usually only after the car has been sitting for a while.

The o2 sensor is a wear item, so replacing it won't be a bad thing, even if it doesn't fix the problem. NGK/NTK or Denso are the brands you want to use. Very few people have luck with Bosch sensors, and they usually end up being a waste of money.

[eazyduzit509]

The o2 sensor tells the ECU how much fuel to send, which is why the ECU sees it as a fuel system problem.

My code 43 comes on at about 55mph, and usually only after the car has been sitting for a while.

The o2 sensor is a wear item, so replacing it won't be a bad thing, even if it doesn't fix the problem. NGK/NTK or Denso are the brands you want to use. Very few people have luck with Bosch sensors, and they usually end up being a waste of money.

Good info, thanks Deev.

[Nurega]

The o2 sensor tells the ECU how much fuel to send, which is why the ECU sees it as a fuel system problem.

oh, that does make sense. Thank you, Deev. I'll look into the DIYs on replacing them myself.

[CB7Man]

Super easy to change on these accords....unless you had my car!
The EX is located on the downpipe, just after the collector.
I bought a O2 sensor wrench and it rounded off the O2....
So I took the downpipe off and took the GIANT channel locks to it....wouldnt budge.
Next day installed the downpipe from my coupes old F22, and sold the header/F'ED Downpipe locally

Ya the 43 is O2 sensor almost exclusivly
Its happened on both my CB's
The "test" is to hold RPM's between 2200 and 2500

[ikayto]

day 1 of my $40 NGK sensor. so far so good.

only problem with code 43 is your ecu stop reading from the o2 and runs off a standard all purpose base map that dumps gobs of fuel at all rpms. So you lose around 2-3mpg and performance.

[Nurega]

Wilson, where did you find it for $40? I can't find it under $55 online.

[deevergote]

Man, they keep getting cheaper and cheaper! I used to think $80 was a steal!

[wed3k]

we oughta sticky my code 43 post in beginners tech section

EX can use the LX, just shorten wires and swap electrical connectors. those are roughly 36 dollars via denso.

[CB7Man]

there 5 finger discounted at the junkyard.
I have like 3

[wed3k]

they probably dont work.

[CB7Man]

they probably dont work.

idk two of them do haha

[crazymikey]

My code 43 was 02 sensor.

After replacing plugs,wires and fuel filter, it still hesitated and threw the code. New 02 sensor cured it all, and I ended up doing some good maintenance while trying to diagnose it with the new parts.

My 02 sensor was on the downpipe as well. I was expecting it to be a SOB to get out, so I sprayed it with PB Blaster and got a big wrench on there and gave it all I got. Damn thing twisted right out as if it was finger tight and I bashed 3 of my knuckles off the floor of the car in the process.

But yeah, super easy to change.